It is not possible to set cache timeout in milliseconds

[onetocny]

First of all I would like to thank you for CacheOutput library which is really helpful. Currently it is possible to set caching time in seconds only. This is fine for most of cases, but it becomes a problem when you want to set timeout lower than second. My suggestion is to add another two properties (for server and client) of type TimeSpan to the CacheOutputAttribute class. I did a quick code overview and it should not be a big deal to make this working. if this is wanted I am open to implement it and share pull request with the community.

[onetocny]

Created pull request with suggested functionality #264.